Stabilization of oxidizable organic materials



Patented Apr. 4, W4 2 STABHJIZATION OF @XIDIZABLE ORGANIC MATERIALS Lon-an 0. Buxton, Belleville, N. 5., assignor to National Oil Products Company, Harrison, N. 1., a corporation of New Jersey No Drawing. Application June 11, 1941. Serial No. 397,547

16 Claims.

- This instability of oils and fats tends to be accentuated by conventional refining processes, since in many cases the refining destroys or removes the natural antioxidants contained in such substances. This characteristic instability is particularly undesirable in connection with fat-soluble vitamin-containing oils, since these oils not only show the typical tendency to become rancid upon exposure to air, but also tend to lose a considerable portion of their valuable vitamin activity. Other oxidizable organic substances manifest their characteristic instabilities in different fashions, but in practically every case their instability is highly undesirable.

As a result of the instability shown by many oxidizable organic substances, many attempts have been made to increase the resistance of these substances to the action of oxidizing influences. For example, it has been proposed to stabilize oils and fats by adding certain crude vegetable oils thereto, the theory being that since the crude vegetable oils suggested for use contain natural antioxidants, these antioxidants would serve to stabilize the oils and fats. This proposal has, however, not met with any particular success because of the fact that since the vegetable oils do not contain very high percentages of the antioxidants, disproportionately large amounts of the oils have to be added to the substances to be stabilized in order to achieve the desired antioxidant efiect.

it has been suggested that solvents, such as ethyl alcohol, would be capable of extracting effestive antioxidants from oil-free vegetable meals. This proposal has several disadvantages. In the first place, the antioxidants extracted from the meals are generally not completely oil-soluble, so that in some cases it is not possible to form cornpletely homogeneous mixtures of these antioxidants with substances such as oils and fats. In

the second place, the antioxidants extracted in this manner from oil-free vegetable meals may have extremely dark colors and unpleasant odors and are generally obtained in very poor yields. The result of these disadvantages has been that the suggested method has not met with any substantial degree of commercial success.

Also it has been proposed to extract antioxidants from oil-free vegetable meals by means of water. This proposal has much the same disadvantages as the last mentioned one. As antioxidants prepared by water extraction are not oil-soluble, they are not altogether suitable for use for the protection from oxidative changes of substances such as oils or fats.

It has also been proposed to recover antioxidants from vegetable oils by saponifying the oils, separating the unsaponifiable portions of the oils and recovering antioxidants from these unsaponifiable portions by successive extractions and fractionations. This proposal has likewise not been commercially successful because it entails the destruction by saponification of the valuable vegetable oils, thereby rendering the process highly uneconomical, and because the saponification destroys the antioxidant properties of certain of the materials contained in the oils; moreover, the necessity for carrying out a number of extraction and fractionation steps is clearly disadvantageous.

Because of the many disadvantages inherent in prior processes for the production of antioxidants, there is still a considerabl demand in the industry for a simple, economical and effective method for preparing antioxidants which .will accomplish the desired results. Furthermore, due to the recent. large scale developments in the production and use of fat-soluble vitamin-containing oils, the need for such antioxidants has become particularly acute due to the well known instability of vitamins contained in such oils.

It is an object of this invention to provide stabilized oxidizable organic substances having greater resistance to the action of oxidizing forces.

It is a more specific object of. this invention to provide improved antioxidants capable of stabilizing fat-soluble vitamin-containing oils.

Another object of this invention is to provide a simple and economical process for the production of highly eifective antioxidants.

In my copending application Serial No. 351,909, filed August 8, 1940, a process is described where by fatty materials containing natural antioxidants may be treated so as to separate and concentrate the antioxidants. The antioxidants produced by the process of the above-identified invention are eminently suitable for use in the stabilization of oxidizable organic substances oi an oily or fatty nature, since they are highly active and since they may be easily blended with such substances to form completely homogeneous, stable mixtures.

It has now been found that highly efiective antioxidants possessing all the desirable characteristics of those obtained by the process of my copending application Serial No. 3519139 may be economically produced from oil-bearing meals, seeds, nuts, grains and similar oil-bearing solids with which they are asociated'by subjecting such materials to solvent extraction with a suitable solvent, whereby the antioxidants become conccntratcd in the solvent extract. 1 have found that the solvent extraction of such materials yields products containing antioxidants in extremely active condition, and that such extracts may be blended with oxidizable organic substances to form mixtures extremely resistant to deteriorative oxidation, My invention is primarily concerned with the stabilization of oxidizable organic substances 01' an oily or fatty-nature, since my antioxidants may be easily blended with such substances to form completely homogeneous, stable mixtures. A preferred embodiment of my invention involves the stabilization of fat-soluble vitamin-containing oils. since the addition of my extracts to such' oils not only prevents the development of undesirable rancidity and discoloration, but stabilizes the vitamin content of theoils so that there'is relatively little destruction of either the vitamin A or D contained in the oils even after'prolonged exposure to atmospheric-conditions. The-yields obtained in accordance with my-process are unusually hieh and the solvents employed are all readily available at comparatively low cost; as a result. my novel process for the preparation of antioxidants is extremelyeconomical.

The oil-bearing solid from which the anti-- naturally-occurring antioxidants or mixtures thereof. The term "fattyoil-bearing solid" is used throughout the specification and claims to include solids of plant or animal origin containing fats. fatty oils or fatty waxes. The oilbearing solid may contain all the oil, fat or wax present in said solid in its natural state, or it may have had a substantial portion of the fatty material removed. There are many such solids containing natural antioxidants known to the art. Thus vegetable materials such as soybeans. wheat bran. wheat germ, corn germ, corn grain, oats, rye, olives. sesame seed, cottonseed, cocoa bean,palm kernels, copra. rice, rice germ,'fiax seed, teaseed, hemp seed, perilla seed, alfalfa seed, celery seed, mustard seed,rape seedpoppy seed, Sufiflower seed, pumpkin seed,-melon seed, peanuts. and the nine, may be treated. Another group of. materials that may be employed are fish livers such as the livers of cod, halibut, time, shark, etc, as wellas the fish themselves. (E ther fish from which antioxidants may be obtained include sardine, menhaden, herring and similar Other materials which may be treated in accord" ance with my invention are tomato seeds, grape seeds, peach kernels, egg yolks, and whale livers. I prefer to produce my antioxidants from oil bearing vegetable materials, and in the detailed description hereinafter given, particular reference will be made to the treatment of such vege lit aseaevs that other oil-bearing solids containing antloxidants may be used, if desired.

As hereinabove pointed out, the antioxidants are recovered from materials bearing Iatty oils with which they are associated by extraction with a suitable solvent. The solvent employed in accordance with my invention may be selected from a large number of aliphatic solvents round to be useful as a result of extensive experimentation; the choice of the solvent will depend to some extent upon the properties or the material to be treated, as will become more evident from the detailed description hereinafter given. My results have indicated that the solvents preferably employed are members of well recognized chemical classes; I' have also found that the number of carbon atoms in the solvent to be used is a particularly important factor in determining the availability thereof for use in the practice of my invention. The following table embodies the results of my experiments and sets forth the classes of olvents which I h ve found to be particularly useful in the recovery of antioxidants.

Table I Solvents falling in the classes above listed are all liquid aliphatic organic compounds having the properties of being substantially miscible with fatty materials at temperatures above room temperature, i. e., 20 C. to 25 C., and partially immiscible therewith at temperatures substantial y below room temperature, and my experiments have shown that solvents falling within this class of compounds may be used in the practic of my invention. In addition it will be noted that my preferred solvents possess relatively low freezing points.

In order to more i'ully illustrate the nature of the solvents which I may employ, a partial list thereof is herewith given; it is to be understood, however, that this list is not intended to be complete, but is merely illustrative of the solvents which may be employed. Thus I have found that the following solvents may be used: n-

propyl alcohol, isopropyl alcohol, n-butyl alcohol,

n-amyl alcohol, isoamyl alcohol, secondary amyl alcohol, furfuryl alcohol, allyl alcohol, diacetone alcohol, p-hydroxy ethyl acetate, methyl formate,

ethyl formate, ethyl acetate, methyl acetate, isopropyl acetate, glycol diformate, glycol diacetate, methyl levulinate, ethyl levulinate, methyl aceto acetate, ethyl aceto acetate, methyl furoate, vinyl acetate, furfural, propionaldehyde, crotonaldehyde, acetone, methyl ethyl ketone, acetonyl acetone and propylene chlorhydrin. Mixtures of these solvents may also be used. It will be noted that all these solvents belong to that class of aliphatic organic compounds which has the property of being miscible with fatty oils at temperatures above room temperature and partially immiscible therewith at temperatures substantially belo'i room temperature; furthermore, it will be noted that the majority of these solvents have relatively low freezing points.

Occasionally it may be found that certain oi the solvents hereinabove mentioned may be too miscible with some of the fatty materials contained in the oil-bearing solids which may be treated by my invention to effect a separation of antioxidants therefrom; thus, for example, acetone is too miscible with many fatty materials to accomplish the purposes of this invention. However, this condition may be easily corrected by diluting the solvent either with a small amount of water or with some liquid. aliphatic organic solvent relatively immiscible with fatty materials. In general it may be said that the effect of diluting any of the above solvents with water will be to render the solvent more immiscible with fatty materials, so that if difficulty is encountered in effecting proper separation of the antioxidant extracts from the fatty materials contained in the oil-bearing solids, this difliculty may generally be overcome by the addition of a small amount of water to the solvent.

The solvents I prefer to employ in the practice of my invention are the aliphatic alcohols containing from 3 to 6 carbon atoms; of these so]- vents isopropanol and diacetone alcohol have proved to be the most successful. The presence of the hydroxyl group seems to impart to these solvents properties which make them particularly useful for my purposes; whether this factor is due to some activating influence possessed by this group is not known.

In carrying out the extraction of the antoxidants from the oil-bearing solid with which they are associated, the solid which is to be treated is preferably ground, chopped, macerated or otherwise sub-divided before mixing with the solvent to be employed. Frequently the solid to be treated may be obtained commercially in the form of an oil-bearing meal, e. g., wheat germ meal, soybean meal, corn germ meal, cottonseed meal, wheat bran, ground corn, fish meal, etc. The relative proportion of oil-bearing solid to solvent may vary widely; preferably the ratio of solvent to solid should be greater than one, and in most cases mixtures containing between about 5% and about 25% of oil-bearing solid are most suitable. It is preferable to cause substantially all of the oil contained in the oil-bearing solid to dissolve in the solvent; when employing the preferred solvents of my invention, complete lution of the oil is ordinarily effected most readily by heating the mixture to a temperature substantially above room temperature. However, it is not necessary to cause the oil to dissolve completely in the solvent, since highly active antioxidant fractions may be extracted from the oilbearing solid by agitating the comminuted solid with the solvent at a temperature such that only partial solution of the oil contained in the oilbearing solid is effected. The extraction is preferably carried out in an inert gas atmosphere; furthermore, if fat-soluble vitamins are present in the oil-bearing solid being extracted'it is not advisable to heat the mixture to temperatures substantially in excess of 175 C. if recovery of the vitamins is desired.

The antioxidant fraction extracted from the oil-bearing solid may be recovered in any suitable manner. When operating in accordance with the preferred embodiment of my invention, i. e., when the oil contained, in the oil-bearing solid is completely dissolved in the solvent at somewhat elevated temperatures, the recovery of the antioxidant extract is most conveniently accomplished by cooling the mixture to a temperature substantially below room temperature, e. 3., between about 0 C. and about -70 0., at which temperatures only a relatively small amount of the oil contained in the oil-bearing solid will be soluble in the solvent, but the major portion of the antioxidantscontained in the oil-bearin solid will be soluble in the solvent. The solvent fraction containing the major portion of the antioxidants contained in the oil-bearing solid and only a very small amount of the oil contained in said solid, is removed from the mixture by filtration, centrifugation, decantation, or some other suitable means, filtration being preferred. The comminuted solid acts as afilter-aid and thus facilitates the separation of the solvent fraction from the oil insoluble therein at the lowered temperature.

If desired, the mixture may be filtered hot and the filtrate cooled to a temperature substantially below room temperature, e. g., between about 0 C, and about 70 0., whereby two layers form. The solvent layer will then be found to contain the major portion of the antioxidants of the original material. When the process is carried out in this manner, it is preferred to concentrate the filtrate to about one-half to one-third its volume before cooling, as usually more efiicient results are thereby obtained.

The solvent layer obtained from the extraction of the oil-bearing solid may be filtered, if desired. and then treated to remove the solvent therefrom, e, g., by vacuum distillation, whereby an extract is recovered containing relatively large amounts of highly active antioxidants. If desired, water may be added to the extract in order to precipitate some of the glycerides contained therein or some of the sterols may be removed; however, these steps are not essential, since the glycerides and sterols do not inhibit the antioxidant properties of the extract. If the extract contains an excessive amount of free fatty acids, these are preferably removed by treatment with alkali in a solvent medium or by other. suitable methods. The extract ordinarily possesses the characteristic odor and color of the oil contained in the solid from which it is obtained, and is generally slightly more viscous than said oil. The tests carried out on vegetable meal extracts indicate that the iodine values of the extracts are lower than those of the vegetable oils which are obtained from the meals. If a fish meal or comminuted fish livers are treated by the process of my invention, it will be found that the extract contains a considerable portion of the vitamins P of said fish material concentrated therein.

My novel antioxidants may be employed for the stabilization of all types of oxidizable organic substances, particularly those of a fatty nature, i, 2., fatty oils, fats, waxes, soaps, vitamin concentrates, etc. Thus oils and fats of animai,

vegetable or fish origin, such as cod liveroil, tuna liver oil, shark liver oil and other fish liver oils, as well as vitamin concentrates or vitamin-containing fractions obtained from such oils; corn oil, cotton seed oil, soybean oil, and other vegetable oils; fats such as butter, margarine, lard, hydrogenated shortenings, palm oil, etc; soaps of higher fatty acids; and compositions contain ing such fatty materials as essential ingredients, as, for example, cookies, cakesfcrackers, breakfast cereals, etc., as well as food emulsions such as mayonnaise, may all be suitably stabilized, in accordance with my invention. Furthermore, substances such as sulfonated oiis and other fonated fatty compounds, amides, mono and diglycerides and other fatty substances which to become rancid upon exposure to air may be treated by my invention. Other materials subject to oxidative changes which may be protected with the products of my invention include cos metics, such as face cr ams, hand lotions, shav ing creams, etc.; g sofine, mineral oil, lubricating oils, rubber, etc. The amount of the extract added to the material to be stabilized may vary considerably, depending upon the activity of the extract and the degree of instability of the material to be stabilized; I have found that oils or fats containing anywhere from about 0.1% to about 20%, preferably from about 0.5% to about of my antioxidant extracts show striking improvements in their stability,

My antioxidants are particularly adapted for the stabilization of fat-soluble vitamin-containing oils or concentrates, as well as vitamin-containing fractions recoverable from such products by vacuum distillation, solvent extraction or other processes. This is extremely fortunate, for antioxidants capable of stabilizing such products have not as yet been made available on a wide scale. My antioxidants may be added to such materials in any suitable amount without imparting undesirable color, odor, taste or toxicity thereto; furthermore, the incorporation of my antioxidants in such vitamin-containing products yields vitamin compositions of a stability such that they may be handled more easily and economically than compositions heretofore obtainable. These stabilized vitamin compositions may be empioyed in the same manner as ordinary vitamin compositions and thus may be incorporated in food materials of all types, emulsified to form valuable emulsions or put to other appropriate uses.

Substances of a fatty nature stabilized by the addition of my novel extracts thereto may be heated to elevated temperatures without substantially affecting the activity of the antioxidants; moreover, the heating of vitamin-containing oils stabilized by the addition oi my extracts does not, substantially reduce the vitamin activity of the oils. As a matter of fact, 1' have found that by adding the antioxmant extracts of my invention to substances of a fa nature having undesirable tastes and odors and subsequently heating the mixtures to elevated temperatures, e. 110 to 130 6., the undesirable tastes and odors of the sub stantially minimized,

In order to illustrate the improved stability" disdays and then measuring the percentage of the vitamin A destroyed.

Table 11 Vitamin A destroyed after-- 6 days 14 days 20 days Percent Percent Percent Crude sharli eroii 6.28 18.1 30.6 Refined she 1i 22.0 49. 5 78.7 Refined she; iver oil+5% of an antioxidant extract from corn germ meal 7.65 15. 7 22. 5 Refined shark liver oil+5% of an antioxidant extract from pressed wheat germ meal 5. 34 12.4 22 3 Refined shark liver oil+5% of an antioxidant extract from cottonseed meal 8.5 23. 5 34. 0 Refine' shark liver oil +5% of an antioxidant extract from crude wheat germ meal 2. ll. 6 18.2

From the above it can readily be seen that highly active antioxidant extracts may be prepared by the process of my invention from oilbearing materials containing natural antioxidants.

In copending application of Dombrow, Serial No. 343,558, filed July 2, 1940, a process is disclosed and specifically claimed for the solvent extraction of fish liver oils to separate and concentrate the vitamins contained therein. A modification of the process of the present invention as hereinabove described which I have found to be particularly successful involves extracting a fish liver oil and an oil-bearing vegetable meal containing natural antioxidants with one of the hereinabove named solvents. As pointed out in the copending Dombrow application hereinabove referred to, the extraction of the fish liver oil effects a concentration of the vitamins in the solvents; furthermore, the antioxidants of the vege table meal are also concentrated in the extract, so that a highly potent, extremely stable extract is recovered. A simila: extraction of a mixture of an oil-bearing vegetable meal and a fat-soluble vitamin concentrate yields an extremely stable extract constituted chiefly of the concentrate and the antioxidants of the meal.

While my invention is primarily concerned with the stabilization of oxidizable organic substances of a fatty nature, other oxidizable organic substances, such as non-fatty substances containing vitamin C, pyrethrum, essential oils and other materials known to the art may be stablized by treatment with my novel extracts.

The following examples are illustrative of the method of producing the extracts of my invention; amounts are given in parts by weight.

Example I 206 parts of fresh wheat germ meal were mixed with 800 parts 99% isopropanol and the mixture heated to about C. while thoroughly in the presence of N2 gas. The mixture was then slowly cooled with occasional mixing to about l.8 C. The mixture was then filtered. he residual meal mass was mixed with another h of :esh 99% isopropanol and treated esbefore. The filtrates which were ciear were combined and the solvent reduced pressure and in an inert atmosphere of N2 gas. The resulting product was very antioxidant. The antioxidant extract had an iodine value of 120, whereas the wheat germ oil which was obtained on extracting the residual meal mass with a fat solvent at room temperature had iodine value of 129.

. oxidant.

Example II This experiment was performed exactly as in. Example I except that 91% isopropanol was used in place of 99% isopropanol. The resulting product had very highly active antioxidant properties. In this case the antioxidant extract had an odine value of 116 as compared to 129 for the wheat germ oil. The antioxidant extract was dissolved in ethylene dichloride and filtered to remove any insoluble material. The ethylene dichloride was then removed from the filtrate under 9. reduced pressure and in an inert atmosphere of N2 gas. The resulting product was a highly active antioxidant which was brilliantly clear and completely oil-soluble.

Example III This experiment was performed exactly as in Example I except that distillers dried corn solubles, a corn by-product of the distilling industry, were treated instead of wheat germ meal, and 91 isopropanol was used in place of 99% isopropanol. The resulting product was a very strong anti- Example I V 100 parts soybean meal were mixed with 400 parts 95% diacetone alcohol and the mixture heated to about 80 C. while stirring in an inert atmosphere of N2 gas. The mixture was then filtered hot and the residual meal-mass extracted with another batch of fresh 95% diacetone alcohol. The filtrates were combined and the resulting solution was concentrated to about one third its original volume. This concentrated solution was then slowly cooled to about -25 C. After standing at this low temperature for 3 days, the mixture was filtered and the solvent removed under reduced pressure. The product which was obtained was a highly active antioxidant.

Emample VI 100 parts of a meal produced by crushing-soybeans were mixed with 400 parts of 91% isopropanol and the mixture brought up to 60 C. while thoroughly agitating the same in the presence of nitrogen. The mass was then gradually cooled to 18 C. and maintained at this tem-,

perature until the supernatant solvent layer was substantially clear. The supernatant solvent layer was then recovered by filtration. The residual meal was extracted twice more in accordance with the foregoing procedure. The brilliantly clear filtrates were combined and the isopropanol removed by distillation under reduced pressure and under an atmosphere of nitrogen whereby an excellent antioxidant composition resulted. The residual meal was then extracted with 99% isopropanol at 40 C. to remove the oil therefrom. The recovered oil was found to be very light in color and substantially free of break constituents and free of the characterlstic grainy or beany odor usually associated with crude soybean oil. 'From this process not only is the desired antioxidant obtained but also a highly'refined oil.

From the above description it will be evident I that my invention provides a new and highly useful method for the recovery of naturally-occurring antioxidants from oil-bearing solids with which they are associated. My invention provides a process which is highly economical and which furnishes highly active antioxidants; furthermore, since my process does not involve subjecting the oil-bearing solid to be treated to saponification or any other chemical change, the

residual material is particularly valuable for a wide variety of purposes after the removal of the antioxidants therefrom. The process is further adapted for both the recovery of antioxidants and the refining of the oil itself by the removal of the .break constituents. Inextracting oilfrom the seed meal after the antioxidants have been recovered, any suitable fat solvent may be employed, such, for example, as 99% isopropanol, ethylene dichloride, trichlorethylene, hexane, etc. It is apparent from the foregoing that my process provides for the recovery of valuable antioxidants as well as the production of non-break" oils. Moreover, my invention provides a highly useful process for the stabilization of fat-soluble vitamincontaining oils and ,concentrates, and thus satisfies the demand of the industry for such products. Because of these factors it will be evident that my invention will be extremely useful to all those engaged in the production and stabilization of fatty materials. y

Since certain changes may be made in carrying out the above process without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described,

and all statements of the scope of the invention,

which as a matter of language might be said to fall therebetween.

Having described my invention, what I claim as v new and desire to secureby Letters Patent, is:

1. A process for obtaining antioxidants from vegetable oil-bearing solids containing natural antioxidants, which comprises pontacting a vege table oil-bearing solid containing natural antioxidants with a solvent selected from the group consisting of aliphatic and alicyclic monohydroxy alcohols containing from 3 to 6 carbon atoms, esters formed by the reactionof aliphatic and alicyclic alcohols with aliphatic monocarboxylic acids, said esters containing not more than 8 carbon atoms, aliphatic and alicyclic aldehydes containing not more than 6 carbon atomsand aliphatic ketones containing notmore than 6 carbon atoms at a temperature above room temperature, cooling the mass to a temperature within the range of 0 C. to 70 0. whereby layers are formed and separating the solvent layer contain ing the highly active antioxidant extract from the remainder of the mass.

2. A process for obtaining antioxidants from vegetable oil-bearing solids containing natural antioxidants, which comprises contacting a vegetable oil-bearing solid containing natural antioxidants with a solvent selected from thegroup consisting of aliphatic and alicyclic monohydroxy alcohols containing from 3 to 6 carbon atoms, esters formed by the reaction of aliphatic and alicyclic alcohols with aliphatic monocarboxylic apids, said esters containing not more than 8 carcan atoms, aliphatic and alicyclic aldehydes containing not more than 6 carbon atoms and aliphatic ketones containing not more than 6 carbon atoms at a temperature above room temperature, the ratio of solvent to oil being greater than one, cooling the mass to a temperature within the range of C. to --'70 C. whereby layers are formed and separating the solvent layer solution containing the highly active antioxidant extract from the remainder of the mass.

3. A process for obtaining antioxidants from vegetable oil-bearing solids containing natural antioxidants, which comprises contacting a vegetable oil-bearing solid containing natural antioxidants with an aliphatic monohydroxy alcohol containing from 3 to 6 carbon atoms at a temperature above room temperature; cooling the mass to a temperature below 0 C. jwhereby layers are formed and separating the solvent layer containing the highly active antioxidant extract from the remainder of the mass.

4. A process for obtaining antioxidants from wheat germ meal, which comprises contacting oilbearing wheat germ meal with isopropanol at a temperature above room temperature so as to form a solution in the isopropanol of the oil contained in the meal, cooling the mass to a temperature below 0 C. whereby layers are formed and separating the solvent layer containing the highly active antioxidant extract from the remainder of the mass.

5. A process for obtaining antioxidants from corn germ meal, which comprises contacting oilbearing corn germ meal with isopropanol at a temperature above room temperature so as to form a solution in the isopropanol of the. oil contained in the meal, cooling the mass to a temperature below 0 C. whereby layers are formed and separating the solvent layer containing the highly active antioxidant extract from the remainder of the mass.

6. A process for obtaining antioxidants from soybean meal, which comprises contacting oilbearing soybean meal with isopropanol at a temperature above room temperature so as to form a solution in the isopropanol of the oil contained in the meal, cooling the mass to a temperature below 0 C. whereby layers are formed and separating the solvent layer containing the highly active antioxidant extract from the remainder of the mass.

'7. A process for the recovery of antioxidants from fatty materials with which they are associated, which comprises contacting a mixture of a fish liver oil and an oil bearing vegetable meal containing natural antioxidants with a solvent selected from the group consisting of aliphatic and alicyclic monohydroxy alcohols containing from 3 to 6 carbon atoms, esters formed by the reaction of aliphatic and alicyclic alcohols with aliphatic monocarboxylic acids, said esters containing not more than 8 carbon atoms, aliphatic and alicyclic aldehydes containing not more than 6 carbon atoms and aliphatic ketones containing not more than 6 carbon atoms at a temperature above room temperature, cooling the mass to a temperature within the range of 0 C. to C, whereby layers are formed and separating the solvent layer containing the highly active antioxidant extract from the remainder of the mass.

8. A process for obtaining a refined "nonbreak oil from oil-bearing solids, which comprises contacting an oil-bearing vegetable seed meal with a solvent selected from the group consisting of aliphatic and alicyclic monohydroxy alcohols containing from 3 to 6 carbon atoms, esters formed by the reaction of aliphatic and alicyclic alcohols with aliphatic monocarboxylic acids, said esters containing not more than 8 carbon atoms, aliphatic and alicyclic aldehydes containing not more than 6 carbon atoms and aliphatic ketones containing not more than 6 car-- bon atoms at a temperature above room temperature, cooling the mass to a temperature below 0 C. whereby layers are formed, separating the solvent solution containing the break.constituents and extracting the oil-meal mass with a fat-solvent to obtain an oil substantially free from "break" constituents.

9. A process for obtaining a refined nonbreak" oil from oil-bearing solids,.which comprises contacting an oil-bearing vegetable seed meal with isopropanol at a temperature above room temperature, cooling the mass to a temperature below 0 0. whereby layers are formed, separating the isopropanol solution containing the break constituents and extractingthe oil-meal mass with a fat-solvent to obtain an oil substantially free from break constituents.

10. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim 1.

11. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim 2.

12. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim 3.

13. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim 4.

14. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim 5.

15. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim 6. l

16. A highly active natural antioxidant concentrate prepared in accordance with the process set forth in claim '7.

LORAN O. BUXION. 

